Accurate Mag 3.775" .338 Lapua mags

Hi there guys. I'm in the process of building a .338 Edge. Ive purchased a DBM bottom metal from Dave out at PT&G in the 3.775" length but I'm learning that on the Edge that can be limiting as most loads run in the 3.80ish" range. I can purchase the CIP length of 3.850". Was wanting to know what the actual internal measurements were for COAL on the Accurate Mag magazine in 3.850"? If it is actually 3.850" or less and if the 3.850 is required to take full advantage of the Edge performance gain over the .338 RUM or if the 3.775" will do fine? Thanks guys.

You could even look at Seekins mags. The mag inside measures at 3.900. I went this whey for my 338 Norma Improved. Has a long throat for the big Bergers. Also doing one in a 338 necked down to 7mm. Finally found some very long bullets that are close to 3.9 when done.

My CIP accurate mag measured out at 3.75 coal. The CIP length is 3.85 outside not COAL. My edge was throated for 3.75 with a 300 smk so I didn't have any problems. I was not ncessarily taking advantage of its full potental but I had great accuracy and was shooting a 300 smk at 2800 out of a 29" barrel.